Route 4 East

Walkthrough
Once through Mt. Moon, you will come out near Cerulean City on the eastern portion of Route 4. More Wild Pokemon can be found on this side of Route 4, which will lead you straight into Cerulean City where the next Pokemon Gym is located.

Wild Pokemon
Grasses:
Spearow (40%): Levels 7-12
Rattata (35%): Levels 7-12
Ekans (20%): Levels 7-12
Psyduck (5%): Levels 7-12

Grasses - Special Spawns:
Charmander: Levels 3-8

Waters:
Tentacool (45%): Levels 7-12
Magikarp (45%): Levels 7-12
Tentacruel (10%): Levels 7-12

Sky:
Spearow (60%): Levels 3-56
Fearow (40%): Levels 3-56

Sky - Special Spawns:
Dragonite: Levels 3-56
Charizard: Levels 3-56
Articuno: Levels 3-56
Zapdos: Levels 3-56
Moltres: Levels 3-56

Obtainable Items
Poke Balls: Within Hill Near Mt. Moon Exit
Paralyze Heal: South Of Mt. Moon Exit
Razz Berry: Within Eastern Bush (Found By Pokemon)
Repel: Southern Path
Great Balls: Behind Bushes Near Cerulean City Entrance


Post Game
Walkthrough
After defeating the Elite Four and starting the Master Trainers Challenge, you will find a number of Master Trainers on the eastern portion of Route 4. In total, there are three Master Trainers for you to defeat.

Trainers
Lass Rena (Master Trainer): Level 65 Bulbasaur
Scientist Herbert (Master Trainer): Level 70 Ekans
Swimmer Camille (Master Trainer): Level 75 Golduck